AAC to MP4 - dbpoweramp not preserving tags?

[etuttle]

Greetings. I was excited to find DMC and it's ability to convert raw AAC files to MP4 format (losslessly). I have a large collection of music that was ripped using winamp's raw AAC encoder. The files are all tagged by winamp as well. I want to be able to play these songs with iTunes or another PC player, so I need to repack them into mp4 format.

I downloaded and installed the folowing:

dMC-r10.exe
dBpowerAMP-codec-aactomp4.exe
dBpowerAMP-codec-mp4-aac-decode.exe

And tested by converting one of the .aac files. Unfortunately, the tags weren't preserved.

I further investigated by mousing over the original .aac file. Indeed, dmc can read the tags that winamp encoded. The repacked .mp4 files have no tag info when I mouse over them.

I also tried to install dMC-AAC-Codec.exe and dBpowerAMP-codec-FAAC-mp4.exe although there was no indication these are required. It didn't help.

I assume this is a bug in DMC or one of the codecs? Or am I doing something wrong? Any help very appreciated.

[hans-j�rgen]

Re: AAC to MP4 - dbpoweramp not preserving tags?

AAC files like the ones produced by Winamp cannot carry MP4 (= iTunes) tags, so Winamp uses ID3 tags on them. The file muxer mp4creator (probably used in dbpowerAMP) doesn't take care of any tags, it simply deletes them when muxing from AAC to MP4 or vice versa. To keep the tags during this process the player needs to read the ID3 tags and internally transfer them to MP4 tags on the fly. It seems that dbpowerAMP cannot do this yet, and I'm not sure if e.g. foobar2000 could handle this with the foo_mpeg4u.dll.

Another method is having the file names carrying the metadata information during file muxing, i.e. naming the AAC files with a syntax that could be read by a masstagger capable of MP4 tagging. This would work with foobar2000, and maybe with the tool included in the dbpowerAMP Power Pack, too.

[xoas]

Re: AAC to MP4 - dbpoweramp not preserving tags?

We have had a similar report report the other day (involving m4a files). I have not had problems with losing tag information doing AAC or mp4 conversions in dBpowerAMP Music Converter (dMC) but all my files were created using dMC so the issue might lie there. I do have the Power Pack installed but I have not run across any documentation suggesting that you need Power Pack. I have also gone on to the r11 beta version (I have beta 3, the current version is 5a). I believe I was starting to mess around with AAC/mp4 before switching from dMC r10, but perhpas that may play a role.
But I would urge you to check your Tag Options in dMC Configuration as I have outlined in post 7 of this thread:

http://forum.dbpoweramp.com/showthread.php?t=5755

Let us know what you find.
Best wishes,
Bill Mikkelsen

[etuttle]

Re: AAC to MP4 - dbpoweramp not preserving tags?

Thanks everone for the replies. I played around some more and here's what I discovered.

dMC-r11b5a.exe is able to convert aac to mp4 while preserving tags created by winamp, but there is a terrible bug! While batch converting a group of files from aac to mp4, a random set of the files will not retain their tags. I tried converting many times, with the same set of 19 aac's. Each time, a different set of them would end up with empty tags. About 50% of them on average.

It also seems like there is a background daemon doing the converting that isn't connected to the GUI? The DMC gui would indicate that the batch was done about 1 second. Then, over the next several seconds, I would see the output files growing in size (all growing in parallel). Funky!

This behavior seen with the following installed:

dMC-r11b5a.exe
dBpowerAMP-codec-mp4-aac-decode.exe
dBpowerAMP-codec-aactomp4.exe

I had the tag options set as xaos suggested in the other thread.

I also tried installing the power pack with release 10. That didn't work at all, every file lost it's tag during conversion.

Any more ideas? How to report these bugs in the beta?

[xoas]

Re: AAC to MP4 - dbpoweramp not preserving tags?

How to report these bugs in the beta?

You could start a new thread in the Beta section of this forum. From a practical standpoint Spoon, the man responsible for nearly everything here, will pick up on this from your post. By starting a new thread, however, you might enable more sharing with users who have had your experience, warn potential Beta users of a possible problem, and maybe find an answer to the buggy parts.

You had mentionned earlier that you had had FAAC and AAC encoder codecs installed. Are those still there or did you remove them? You might try reinstalling them now that you are making progress.

I also tried installing the power pack with release 10. That didn't work at all, every file lost it's tag during conversion.

I guess that confirms that the Power Pack alone cannot manage this problem, at least not in dMC r10. Thanks for reporting. What you might try, if you have not done so already with the new r11 beta is to download and install the Tag from Filename utility codec. Perhaps that will help.

Best wishes,
Bill Mikkelsen

[hans-j�rgen]

Re: AAC to MP4 - dbpoweramp not preserving tags?

Another possible problem might be the version of ID3 tags that Winamp uses on AAC files. Maybe it works with v1 tags, but not with v2 or vice versa...

[Spoon]

Re: AAC to MP4 - dbpoweramp not preserving tags?

Make sure you have installed the mp4 decoder as well, that is needed for tag writing (by the mp4 encoder).